Sea ice oddity on ratio of extent to area

Whilst looking at other things I checked the monthly data ratio of sea ice extent to area. This might interest others so here it is.

For Antarctica is constant but for the Arctic the ratio is changing but quite why is not clear to me. Why only the minima?

Plotted as points so the spareness is clear.

I am seeing conflicts between daily and monthly data, so far without any clear reason, although I have suspicions. Irritatingly, again, data is incomplete, no daily area data is published. (and a different dataset is using a bizarre timeline, undocumented)